import java.util.LinkedHashMap;
import storageManager.*;

import java.util.Collection;
import java.util.Map;
import java.util.ArrayList;

class MyLinkedHashMap<K, V> extends LinkedHashMap<K, V> {

    private static final long serialVersionUID = 1;
    //private Map.Entry<K, V> ejectedEntry = null;
    private int cacheSize;

    public MyLinkedHashMap(int hashTableCapacity, float hashTableLoadFactor, boolean b, int cacheSize) {
        super(hashTableCapacity, hashTableLoadFactor, b);
        this.cacheSize = cacheSize;
    }

/*   public Map.Entry<K, V> getEjectedEntry() {
        return ejectedEntry;
    }*/

    @Override
    protected boolean removeEldestEntry(Map.Entry<K, V> eldest) {
        boolean result = size() > this.cacheSize;
        if (result)
        {
        	Block replaced = (Block)eldest.getValue();
        	TinySQL.dump(replaced);
        }
        return result;
    }
}

public class LRUCache<K, V> {

    private static final float hashTableLoadFactor = 0.75f;

    private MyLinkedHashMap<K, V> map;
    int cacheSize;
    public Integer replacedIndex;


    /**
     * Creates a new LRU cache.
     *
     * @param cacheSize the maximum number of entries that will be kept in this cache.
     */
    public LRUCache(int cacheSize) {

        int hashTableCapacity = (int) Math.ceil(cacheSize / hashTableLoadFactor) + 1;
        this.cacheSize = cacheSize;
        map = new MyLinkedHashMap<K, V>(hashTableCapacity, hashTableLoadFactor, true, cacheSize);
        
    }
  
    /**
     * Retrieves an entry from the cache.<br>
     * The retrieved entry becomes the MRU (most recently used) entry.
     *
     * @param key the key whose associated value is to be returned.
     * @return the value associated to this key, or null if no value with this key exists in the cache.
     */
    public synchronized V get(K key) {
        return map.get(key);
    }

    /**
     * Adds an entry to this cache.
     * The new entry becomes the MRU (most recently used) entry.
     * If an entry with the specified key already exists in the cache, it is replaced by the new entry.
     * If the cache is full, the LRU (least recently used) entry is removed from the cache.
     *
     * @param key   the key with which the specified value is to be associated.
     * @param value a value to be associated with the specified key.
     */
    public synchronized void put(K key, V value) {
    	
        map.put(key, value);
    }

    /**
     * Clears the cache.
     */
    public synchronized void clear() {
        map.clear();
    }

    /**
     * Returns the number of used entries in the cache.
     *
     * @return the number of entries currently in the cache.
     */
    public synchronized int usedEntries() {
        return map.size();
    }

    /**
     * Returns a <code>Collection</code> that contains a copy of all cache entries.
     *
     * @return a <code>Collection</code> with a copy of the cache content.
     */
    public synchronized Collection<Map.Entry<K, V>> getAll() {
        return new ArrayList<Map.Entry<K, V>>(map.entrySet());
    }

    public synchronized V remove(K key) {
        return map.remove(key);
    }

    /* Test routine for the LRUCache class.
    public static void main(String[] args) {
        LRUCache<String, String> c = new LRUCache<String, String>(3);
        c.put("1", "one");                           // 1
        c.put("2", "two");                           // 2 1
        c.put("3", "three");                         // 3 2 1
        System.out.println(c.map.getEjectedEntry()); //No entry ejected yet - Print null
        c.put("4", "four");                          // 4 3 2
        System.out.println(c.map.getEjectedEntry());         //1 was just ejected
        if (c.get("2") == null) throw new Error();    // 2 4 3
        c.put("5", "five");                          // 5 2 4
        c.put("4", "second four");                   // 4 5 2
        // Verify cache content.
        if (c.usedEntries() != 3) throw new Error();
        if (!c.get("4").equals("second four")) throw new Error();
        if (!c.get("5").equals("five")) throw new Error();
        if (!c.get("2").equals("two")) throw new Error();
        // List cache content.
        for (Map.Entry<String, String> e : c.getAll())
            System.out.println(e.getKey() + " : " + e.getValue());
            }*/
}